The field of art of the present invention, as represented, for example, by documents FR-A No. 1,399,049 (MONSANTO COMPANY) and EP-A No. 0,018,558 (BAYER AG), already includes the technique of producing polymers heavily laden with granulated minerals and to which they are grafted using a bridging or bonding agent of the organosilane type. This technique, which differs from the process of the invention, does not produce a stable, nonpolymerized, liquid composition.
Document GB-A No. 2,090,602 (MITSUBISHI RAYON CO., LTD.) discloses compositions based on mineral filler, organic acids, and polymerizable monomers dispersed in water under an inert atmosphere. However, said compositions are polymerized hot (at around 50.degree. C.) and over long periods of time (8 hours), making possible only the direct production of reinforced polymers, i.e., directly from hardened polymerized compositions, without the possibility of separating the organic acid/mineral filler reaction from the polymerization reaction by breaking the cycle prior to any polymerization. In other words, the teachings of this patent do not enable, any more than the MONSANTO of BAYER patents, the production of a nonpolymerized liquid composition. A fortiori, no process for their production is contemplated therein.
The teachings of document FR-A No. 2,273,040 (ICI--IMPERIAL CHEMICAL INDUSTRIES, LTD.) disclose polymerizable liquid compositions that include a dispersion of particles from one or more inorganic substances in a polymerizable organic liquid.
Said patent also discloses a process for producing such compositions, as well as the constituents of the latter.
It will be noted, however, that the known process in question involves the mechanical grinding of the inorganic substances in the presence of an environment made up of a liquid monomer and polymer binder.
Said known process is therefore characterized by the chemical adherence of a polymer dispersant onto the inorganic fillers, with said adherence occurring during and as a result of the mechanical grinding operation. This operation takes place over a particularly long period of time (approximately 24 hours), and requires heavy means for its execution.
Without the help of the mechanical grinding, and in the absence of the stated environment, no chemical grafting can occur.